package ex6;


import java.net.*;
import java.io.*;
import java.util.*;

/**
 * QuoteServer is a utility class that allows calling code to 
 * retrieve the latest market value of a given stock by ticker symbol.
 * The QuoteServer obtains the stock value by using the website:
 * <a href="http://quote.fool.com"><tt>http://quote.fool.com</tt></a> <Br>
 * Examples of ticker symbols are <tt>MSFT</tt> and <tt>orcl</tt>.
 * (Note that ticker symbols are not case sensitive.  That is that "MSFT"
 * and "msft" are functionally equivalent.)<p>
 *
 * A valid ticker symbol is one that is currently registered with either
 * the New York Stock Exchange (NYSE) or NASDAQ.
 */


public class QuoteServer {

    protected static final String _URL = "http://quote.fool.com/simple.asp?symbols=";
    protected static final String _TOKEN1 = "mw_simple_last";
    protected static final String _TOKEN2 = "NOBR";
    protected static final String _DELIMITER = "&<>=";    
    public static void main(String[] args) {
        try {
            String str = getLastValue(args[0]);
            System.out.println(args[0] + " has a stock value of " + str);
        } catch(Exception e) { System.err.println(e); }
    }

    /** 
     * 
     * retrieve the latest market value of a stock
     *
     * @requires: tickerSymbol != null
     * @effects: returns a current
     *          value for tickerSymbol as a dollar amount, with a
     *          period separating dollars and cents (eg, "120.50" for
     *          one hundred and twenty dollars and fifty cents)<BR>
     *          unless tickerSymbol is not a valid NYSE or NASDAQ
     *          symbol, when throws NoSuchTickerException<br> or
     *          unless an error connecting to the website or some
     *          other error occurs, when throws WebsiteDataException<BR>
     *          The amount returned may contain commas, for example,
     *          "2,243.87"<br>
     */
    public static String getLastValue(String tickerSymbol)
        throws WebsiteDataException, NoSuchTickerException {
        // the web page queried by the code below can be broken into tokens
        //   with delimiters being <, >, and =.  The token corresponding to
        //   the current stock price comes after the two tokens
        //   mw_simple_last and NOBR.
        String strURLStart = _URL;
        URL urlWebPage = null;
        InputStreamReader isr = null;
        BufferedReader brWebPage = null;
        
        // open the web page for reading
        try {
            urlWebPage = new URL(strURLStart + tickerSymbol);
            isr = new InputStreamReader(urlWebPage.openStream());
            brWebPage = new BufferedReader(isr);
        } catch(Exception e) {
            throw new WebsiteDataException();
        }
        
        // find the line with the stock quote on it
        String strLine = null;
        try {
            while(true) {
                strLine = brWebPage.readLine();
                if(strLine == null)
		{
		    throw new WebsiteDataException("Parse failed!");
                }
                if(strLine.indexOf(_TOKEN1) != -1)
                    break;
            }
        } catch(IOException e) {
            throw new WebsiteDataException();
        }
        
        // find the stock quote in the line
        StringTokenizer strtok = new StringTokenizer(strLine, _DELIMITER);
        while(true) {
            if(strtok.hasMoreTokens() == false)
                throw new NoSuchTickerException();
            if(strtok.nextToken().compareTo(_TOKEN1) == 0)
                break;
        }
        String strNOBR = strtok.nextToken();
        if(!strNOBR.equals(_TOKEN2))
            throw new NoSuchTickerException();
        String strStockValue = strtok.nextToken();


	//format check removed
	
	
        // close the web page stream
        try {
            brWebPage.close();
            isr.close();
        } catch(IOException e) {
            throw new WebsiteDataException();
        }
        
        return strStockValue;
    }
}